The Pacific Ocean Shelf Tracking Array (POST)- A Permanent Continental-Scale Array For The West Coast Of North America: Performance, Applications, & Relevance

David Welch

President, Kintama Research

10-1850 Northfield Rd., Nanaimo, BC V9S 3B3

david.welch@kintamaresearch.org

Tel: (250) 714-0045 Mobile: (250) 739-9044

ABSTRACT

POST, the Pacific Ocean Shelf Tracking array, is currently the world’s largest telemetry system for studying the movements and survival of marine fish. It is also the exemplar for the global Ocean Tracking Network, housed at Dalhousie University, which has received $45M in seed money from the Canadian government and current commitments from partnering organizations that to date have levered a total of $160M of support. OTN is intended to form “an array of POST arrays”, sitting on the continental shelves of all the continents on the planet. As such, POST (& OTN) provide a prime example of what the evolving OOS system might look like for coastal regions.

POST was one of the Census of Marine Life’s original field projects, a natural fit given the CoML’s focus on distribution, diversity, and abundance of marine life. However, POST is also starting to prove itself in addressing key US policy questions for fisheries, and thereby demonstrating the fundamental linkage between these biological questions and vexing high-level policy issues. POST thus forms an interesting example of how the development of a highly quantitative tool looking at basic biological processes can inform and reinvigorate the science of fisheries management—and ocean research.

I review POST from the twin perspectives of (a) technical operation & maintenance of a large-scale ocean observing system and (b) the scientific performance of the array in addressing key questions concerning management of west coast salmon and sturgeon. 2006 saw the deployment of the first phase of the permanent POST array. The permanent array currently has a spatial extent of 2,500 km, and uses a short range wireless link to allow remote data upload to a surface vessel without physical retrieval of the equipment—resulting in a year-round monitoring capability and substantial efficiency in operations. These units have sufficient battery power to operate on the seabed for up to 7 years before replacement is necessary. In situ equipment performance has met or exceeded target performance levels (<10% operational losses per year from all sources), making continuous operation of the system economically feasible. Scientific performance has been excellent, with very high detection rates for tagged fish crossing individual listening lines (~95%). As a result, relatively small numbers of tagged animals can provide statistically rigorous (precise and accurate) estimates of survival at sea over many months or years, as well as seamless measurements in both freshwater and the coastal ocean. This provides the opportunity to begin conducting explicit experiments in the ocean to directly test scientific hypotheses. We will provide several examples to illustrate the methodology and clarify the roles of POST and the global OTN as an important—and unique—coastal monitoring system.